There are over 2000 catheterization laboratories in the U.S. performing over 1 million coronary catheterizations and an equivalent number of non- coronary catheterization procedures per year. Science Research Laboratory (SRL) proposes to develop an improved digital technique for visualizing contrast-filled structures that could be applied in all cases where contrast imaging is currently used with many advantages over current techniques. The technique, Dual-Energy Digital-Subtraction Angiography (DEDSA), uses a proprietary x-ray source that relies on novel anode coatings and x-ray filters to enhance the sensitivity to contrast agent while suppressing features due to tissue and bone. In previous work, SRL demonstrated DEDSA imaging of iodine contrast agent within calibrated anthropomorphic phantoms as well as within excised animal organs. In this program we will include the capability of using a gadolinium contrast agent as well. Gadolinium compounds offer many advantages over iodine for DEDSA imaging, including improved tissue and bone cancellation and lower patient dose, and are currently widely used as MRI contrast agents. The goal of this program is to develop and test a clinical DEDSA prototype capable of performing real-time subtracted imaging of animal subjects. The Phase I program is focused on the development of the dual-spectrum x-ray source that is the basis of DEDSA. This project is being carried out in collaboration with Dr. Melvin Clouse, Radiologist in Chief at Beth Israel Deaconess Hospital, who will coordinate testing of the device on animal subjects in Phase II and III. PROPOSED COMMERCIAL APPLICATIONS: The SRL proprietary DEDSA technology can be offered as part of a new catheterization laboratory or as an upgrade to existing equipment. Coronary procedures involving contrast imaging represent a $5B industry within the United States. With over 2000 catheterization laboratories in the United States, substantial markets in Europe, and expected Asian markets, the potential demand for this technology is substantial. Once demonstrated, SRL will seek a strategic partnership with a supplier of angiography equipment.